1. Field of the Invention
The invention relates to an electrical charging apparatus for charging an electrical energy store of a motor vehicle. The charging apparatus has an electrical connection to connect the charging apparatus electrically to a charging station and to interchange energy with the charging station, an electrical converter that is connected to the electrical connection for interchanging electrical energy with the charging station via the electrical connection and to convert the electrical energy, and a control unit that is connected to the electrical converter to control the interchange of the electrical energy.
2. Description of the Related Art
The invention also relates to an electrical charging station for charging electrical energy stores of motor vehicles. The charging station has an electrical connection to connect the charging station electrically to a mobile charging apparatus and to interchange electrical energy with the charging apparatus. The charging station also has a communication interface for interchanging data with the charging apparatus.
The invention also relates to a charging unit having an electrical charging station and an electrical charging apparatus.
The invention further relates to a method for controlling an electrical charging apparatus. The method includes the steps of connecting an electrical converter to a charging station and interchanging electrical energy between the charging station and the electrical converter by controlling the electrical converter by a control unit.
The charging apparatus, the charging station and the method are used to supply mobile electrical devices, in particular electrical motor vehicles, with electrical energy and to interchange electrical energy between the charging station and the charging apparatus and to control the interchange of the electrical energy.
Known electrically driven motor vehicles and known charging stations are configured to connect the charging apparatus of the motor vehicle electrically to the stationary or public power supply network to charge the electrical energy stores of the motor vehicles. Electrical energy can be transmitted to the electrical energy store of the motor vehicle in either a single-phase or three-phase manner depending on the electrical connection or availability. A transformer converts electrical energy that is transmitted from the stationary public power supply network from alternating current into direct current. As a result, a phase shift occurs between the electrical current and the electrical voltage and accordingly reactive power is transmitted. Furthermore, network asymmetries or a neutral point shift may occur during single-phase transmission of electrical energy to the energy store of the motor vehicle. Excessively high electrical reactive powers that occur when charging motor vehicle or individual phases that have an excessive load, may result in disconnection of the electrical energy transmission.
US 2014/0021917 A1 controls a charging station for motor vehicles by assigning a control unit to each three-phase electrical connection to control the three-phase transmission of electrical energy as symmetrically as possible and hence to avoid asymmetries and neutral point shifts. However, reactive power can still occur and simple single-phase energy transmission is not possible, for example in private households.
An object of the invention is to provide an improved electrical charging apparatus, an improved electrical charging station and an improved method for controlling an electrical charging apparatus, thus enabling reliable and robust electrical energy transmission.